Disazo dyestuff



' PatentedMay. 19 1925;

UNITED lsrArss PATE T OFFICE.

WILHELM BERGDOLT AND LUDWIGJHAUCK, OF LEVERKUSEN, COLOGNE-ON- TEE-RHINE, GERMANY, ASSIGNORS '1'0 EARBENFABRIKEN VORM'. FRIEDR..BA. AND 60., O1 LEVERKUSEN, NEAR COLO'GNE-ON-THE-RHINE, GERMANY.

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Toallwhom itmag concern: Be itknown that we, WILHELM BERGDOLT and LUDWIG HAUGK, citizens of Germany, residing at Leverkusen, near Cologne-onthe-Rh1ne, State of Prussia, Germany, have invented new and useful Improvements in a s ecificatlon.

ur invention relates to the manufacture and production of new and valuable azodyestuffs which dye cotton directly in violet to blue pure shades fast to light which by an after-treatment with metal salts, e. g. copper sulfate change into bluish-violet to violet-blue shades very fast to light The new dyes have most probably the following general formula:

- coon R means a residue of an aromatic amino compound, such as R means a residue of an aromatic aminonaphthol compound, such as The rocess .for their production consists in com ining a diazocompound of the henzene or naphthalene series with the la-methyl- 2-aminobenzoic' acid, further diazotizing and combining with the 2-amino-5-naphthol-7-sulfonic acid compound.

The new dyestuffs are, after being dried and pulverized in the shape of their alkali metal salts, dark brown to black powders coon cl N=N no.5 N=N no.5

l HI

4-methyl-2-aminobenzoic acid and 5.5 di-.

From other components as above mentioned, for mstance 2-ams1dme-4-sulfon1c aold,

reddish-blue coloration.

a Disazo Dyestuif, of which the following is Application Med May 22, {92 4. Serial lid 715,190; v

soluble in water, generally with from a red to violet coloration and in concentrated sulfuric acid generally with from a blue to I They yield upon reduction with stannous chloride and hydro.- chloric acid 4-methyl-2.5-diaminobenzoic acid and aromatic amines.

In order to illustrate our new invention more full the following example is given, the parts eing by weight 24,2 parts of 2.5-dichloraniline-4-sulfonic acid are diazotized in the usual manner with 6.9 parts of sodium nitrite and 28 parts of hydrochloric acid 19 B. The resulting diazocompound is combined with 15,1 parts of 4-methyl-2-aminobenzoic acid in the presence of sodium acetate. Subsequently the solution is rendered alkaline, 6,9 parts of sodium nitrite are added and further diazotized by adding this solution to hydrochloric acid and ice. The-diazocompound thus obtained is then allowed to run into a solution rendered alkaline with sodium carbonate, of 31',5 parts of 2-phenylamino-5- naphthol-7-sulfonic acid. After a short time the combination is complete, the. dyestuff is salted out, filtered ofl and dried.

It is after being dried and pulverized in the shape of itssodium salt a black powder soluble in water with a bordeaux-red coloration andin concentrated sulfuric acid with a blue coloration. It yields upon reduction with stannous chloride and hydrochloric acid 2.5-dichloraniline-4c-sulfonio acid, 4-methyl-2.5-diaminobenzoic acid and 2-phenylamino-6-amino-5-naphthol 7-sul fonic acid. It dyescotton directly in bluish-red shades fast to light, which when after-treated with copper sulfate change into violet-blue shades very fast to light. The

new dyestufi has most probably the formula hydroxy-2.2-dinaphthyl-7 .7 Qdisulfonic acid R meaning a residue of an aromatic compound, R meanlng a residue of an aromatic aminonaphthol compound, which are after COOH N=N HO|B NHO HO S N=N which is after being dried and pulverized in the shape of its sodium salt, a black powder soluble in water with a bordeaux-red coloration and in concentrated sulfuric acid with a blue coloration; yielding upon reduction with ,stannous chloride and hydrochloric acid 2.5-dichloro-anilinei-sulfonic acid, 4-methyl-2L5-diaminobenzoic acid and 45 2-phenylamino-6-amino-5-naphthol-7-sulfonpowders soluble in water with from a red to I violet coloration and in concentrated sulfuric acid generally from a blue to reddishblue coloration; yielding upon reduction with stannous chloride and hydrochloric acid 4-methyl-2.5-diaminobenzoic acid and aromatic amines; dyeing cotton directly generally from violet-red to blue pure clear shades fast to light, which after being after-treated on the fibre with a metal salt change into bluish-violet to violet-blue shades fast to light, substantially as described.

2. The herein described new azodyestufi having most probably the following formula:

In testimony whereof we have hereunto 50 set our hands.

WILHELM BERGDOLT. LUDWIG HAUGK. 

